Partially hydrogenated block copolymer, viscous adhesive composition, viscous adhesive tape, label, modified asphalt composition, modified asphalt mixture, and paving binder composition

Abstract

A partially hydrogenated block copolymer of the present invention includes: a polymer block (A) containing a vinyl aromatic monomer unit as a main component: and a polymer block (B) containing a conjugated diene monomer unit, wherein in a differential molecular weight distribution (B) of a degradation product of the partially hydrogenated block copolymer obtained by an ozone degradation method, a distribution of degree of hydrogenation H, which is given by a maximum peak height in a region of a molecular weight of 800 or more and 3,000 or less, is 0.01 to 0.5.

The invention claimed is: 
     
       1. A partially hydrogenated block copolymer comprising: a polymer block (A) comprising a vinyl aromatic monomer unit as a main component; and a polymer block (B) comprising a conjugated diene monomer unit,
 wherein in a differential molecular weight distribution (B) of a degradation product of the partially hydrogenated block copolymer obtained by an ozone degradation method, a distribution of degree of hydrogenation H, which is given by a maximum peak height in a region of a molecular weight of 800 or more and 3,000 or less, is 0.01 to 0.5. 
 
     
     
       2. The partially hydrogenated block copolymer according to  claim 1 , wherein in a differential molecular weight distribution (D) obtained by subtracting, from the differential molecular weight distribution (B), a differential molecular weight distribution (C) of a degradation product of the partially hydrogenated block copolymer obtained by an osmic acid degradation method, a distribution of degree of hydrogenation H 2 , which is given by a maximum peak height based on a total area in a region of a molecular weight of 200 or more and 1,000,000 or less, is 0.001 to 0.007. 
     
     
       3. The partially hydrogenated block copolymer according to  claim 1 , wherein the partially hydrogenated block copolymer has a degree of hydrogenation of 95 mol % or less based on a total number of moles of the conjugated diene monomer unit. 
     
     
       4. The partially hydrogenated block copolymer according to  claim 1 , wherein the partially hydrogenated block copolymer has a degree of hydrogenation of 10 mol % or more based on a total number of moles of the conjugated diene monomer unit. 
     
     
       5. The partially hydrogenated block copolymer according to  claim 1 ,
 wherein L 2 /L 1  is less than 0.02, wherein 
 L 1  is a length of a perpendicular L drawn to a baseline from an apex of a peak that is a peak in a differential molecular weight distribution (A) of the partially hydrogenated polymer and that corresponds to a maximum molecular weight component, and 
 L 2  is a distance on the perpendicular L between the baseline and an intersection where the differential molecular weight distribution (B) intersects the perpendicular L when the differential molecular weight distribution (B) is superimposed on the differential molecular weight distribution (A). 
 
     
     
       6. The partially hydrogenated block copolymer according to  claim 1 , wherein the partially hydrogenated block copolymer has a vinyl aromatic monomer unit content of 10 to 60% by mass. 
     
     
       7. The partially hydrogenated block copolymer according to  claim 1 , wherein the partially hydrogenated block copolymer comprises a partially hydrogenated block copolymer (d1) comprising: one polymer block (A1) comprising a vinyl aromatic monomer unit as a main component; and one polymer block (B1) comprising a conjugated diene monomer unit as a main component. 
     
     
       8. The partially hydrogenated block copolymer according to  claim 7 , wherein a content of the partially hydrogenated block copolymer (d1) is 20 to 80% by mass based on 100% by mass of the partially hydrogenated block copolymer. 
     
     
       9. The partially hydrogenated block copolymer according to  claim 7 , wherein the partially hydrogenated block copolymer comprises a partially hydrogenated block copolymer (r1) having a radial structure. 
     
     
       10. A viscous adhesive composition comprising 100 parts by mass of the partially hydrogenated block copolymer according to  claim 1  and 20 to 400 parts by mass of a tackifier resin. 
     
     
       11. A viscous adhesive tape comprising the viscous adhesive composition according to  claim 10 . 
     
     
       12. A label comprising the viscous adhesive composition according to  claim 10 . 
     
     
       13. The partially hydrogenated block copolymer according to  claim 1 , wherein the partially hydrogenated block copolymer comprises a partially hydrogenated block copolymer (d2) comprising: a polymer block (A) comprising a vinyl aromatic monomer unit as a main component; and a copolymer block (B2) comprising a conjugated diene monomer unit and a vinyl aromatic monomer unit. 
     
     
       14. The partially hydrogenated block copolymer according to  claim 13 , wherein the partially hydrogenated block copolymer has a weight average molecular weight (Mw) of 100,000 to 500,000. 
     
     
       15. The partially hydrogenated block copolymer according to  claim 13 , wherein a peak temperature of a loss tangent (tan δ) obtained by dynamic viscoelasticity measurement of the partially hydrogenated block copolymer is −50° C. or more and −5° C. or less. 
     
     
       16. The partially hydrogenated block copolymer according to  claim 13 , wherein a peak temperature of a loss tangent (tan δ) obtained by dynamic viscoelasticity measurement of the partially hydrogenated block copolymer is −50° C. or more and −5° C. or less, and a peak height value thereof is more than 0.7 and 1.6 or less. 
     
     
       17. A modified asphalt composition comprising  1  part by mass or more and 20 parts by mass or less of the partially hydrogenated block copolymer according to  claim 1 , based on 100 parts by mass of asphalt. 
     
     
       18. A modified asphalt mixture comprising the modified asphalt composition according to  claim 17  and an aggregate. 
     
     
       19. A paving binder composition comprising:
 20 to 70% by mass of a tackifier resin; 
 20 to 70% by mass of oil; and 
 2 to 15% by mass of the partially hydrogenated block copolymer according to  claim 1 .